Nonreversible odometer

ABSTRACT

A nonreversible odometer for a driven vehicle includes a plurality of driven number wheels which display the total distance traveled by the vehicle. The gear train of the odometer is designed so that an input thereto which increases the total indicated travel of the vehicle is transmitted through the gear train to increase the travel distance displayed on the number wheels. On the other hand, if the input to the odometer is one which would decrease the total displayed travel of the vehicle, the drive between the input shaft and the number wheels is interrupted and no decrease is effected.

United States Patent Wallis 1 Jan. 18,1972

[54] NONREVERSIBLE ODOMETER [72] Inventor: George C. Wallis, Livonia,Mich.

[731 Assignee: Ford Motor Company, Dearbom, Mich.

[221 Filed: July 23, 1970 [21] App]. No.: 64,049

[52] U.S. Cl 235/95, 235/96 [51] Int. Cl

[58] Field otSearch ..235/95, 96, 97, 117, 132

[56] References Cited 9 UNITED STATES PATENTS 1,690,356 11/1928 Zubaty..235/96 X 2,143,550 1/1939 Gilbert.... .....200/52 2,148,768 2/1939Miller .....235/9l 2,342,325 2/1944 Bliss ..235/l44 2,957,625 10/1960Burke et a]. ..235/1 14 3,231,191 l/l966 Berck ..235/l32 3,404,83410/1968 Emery et a]... ....235/ l 32 3,453,420 7/1969 Freese et al.......235/1 32 3,458,127 7/1969 Hermann ..235/95 Primary Examiner-StephenJ. Tomsky Attorney-John R. Faulkner and William E. Johnson [57] ABSTRACTA nonreversible odometer for a driven vehicle includes a plurality ofdriven number wheels which display the total distance traveled by thevehicle. The gear train of the odometer is designed so that an inputthereto which increases the total indicated travel of the vehicle istransmittedthrough the gear train to increase the travel distancedisplayed on the number wheels. 0n the other hand, if the input to theodometer is one which would decrease the total displayed travel of thevehicle, the drive between the input shaft and the number wheels is interrupted and no decrease is effected.

2 Claims, 6 Drawing Figures NONREVERSIBLE ODOMETER BACKGROUND OF THEINVENTION Most driven vehicles are equipped with an odometerwhichrecords the total distance traveled by the vehicle. This indication ofthe total travel of the vehicle is importantto a used vehicle purchaser.The total distance already traveled by the vehicle generally indicatesthe'total distance left for normal usable operation of the vehicle. Thisis particularly true with respect to both certain engine components andcertain components which must be repaired orreplaced at approximatelyfixedincrements of vehicle travel.

To mislead the purchaser of a used motor vehicle, the vehicles odometeris sometimes reset to reduce the total indicated vehicle travelrecorded-thereon. More-particularly, if the normal rotational input tothe odometer is reversed, a reduction is effected in thetotal traveldistance indicated thereon. When the reverse input to the odometeris ata high rotational rate, it is easy to run off a substantial amount ofindicated vehicle travel within a short period of time.

SUMMARY OF THE INVENTION This invention relates to va nonreversibleodometer and, more particularly, to a nonreversible odometer in whichthe driving interconnection between and input member and a displaydevice of the odometer is interrupted if the input member is driven insuch a direction as would result in a reduction in the total indicateddistance on the display device.

In accordance with the teachings of this invention, a nonreversibleodometer for use in a vehicle to indicate the total distance traveled bythe vehicle is constructed in the following manner. An input member ofthe odometer is driven by apparatus responsive to movement of thevehicle. A display device is provided for indicating the distancetraveled by the vehicle. Adrive element for driving the display deviceis connected with the input member so that a displacement is occasionedin the display device in response to the movement of the vehicle.Elements are provided in the interconnection of the display device andthe input member to interrupt the connection when theinput member isdriven in a direction which would result in a reduction in the totaldisplayed travel distance. On the other hand, when the input member isdriven in a direction to increase the total displayed distance, theinterconnection of the inputmember and the drive element of the displaydevice isma'cle by the elementsso that the total displayed traveldistance is increased.

In greater detail, the drive element of the display device isinterconnected with the input member by a drive train. The drive trainhas elements associated therewith which permit the drive train to drivetheldisplay=device only when the input member is driven in av directionwhich increases the displayed distance thereon. When the .input memberis driven to decrease the totaldisplayed travel distance, theinterconnection of the input member and the drive element is interruptedand no decrease occurs in the indicated travel distance of the odometer.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a plan view of anonreversible odometer formed in accordance with the teachings of thisinvention.

FIG. 2 is a view taken along the line 2-2of FIG. 1 showing in greaterdetail a first embodiment of the nonreversible odometer.

FIG. 3 is a partial, cross section view taken along line 3-3 of FIG. 2showing details of the structure of the first embodiment.

FIG. 4 is a view similar to FIG. '2'showing a second embodiment of thenonreversible odometer.

FIG. 5 is a view taken along line 55 of FIG. 4 showing the iSlIUCIUIC ofthe second embodiment in greater detail.

FIG. 6 is a cross section view. taken along line 6-6 of FIG.'4 showingmore details of the structure of the second embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENT General Construction In FIG. 1 anonreversible odometer is shown and generally identified by the numeral10. The odometer has a frame 11 which has sidewalls 12 and 13 as well asa tubular housing 14 extending therefrom. The tubular housing 14 hasan-intemal bearing 16 which supports for rotative movement therewithinan input shaft 17. One end 18 of the shaft is coupled to and driven byan odometer input device which is driven in a known manner by someportion of a motor, vehicle. A gear 19 is formed on the portion of theinputshaft which extends into the space between the side walls of theodometer frame.

A cross-shaft 21 is supported at its right end as viewed in FIG. 1 in abearing surface 22 formed in the sidewall 13 of the frame 11. The otherend of the cross-shaft is supported in a bearing surface 23 formed in aprojecting portion 24 of the frame 11. The cross-shaft has a gear 26formed thereon which is in meshing engagement with the gear 19 of theinput shaft 17. The cross-shaft also has a second gear 27 thereon at itsend adjacent the sidewall 13.

A primary shaft, generally designated by the numeral 31, is supportedfor rotative movement at one end in a bearing surface 32 formed in theback portion oftlie frame II and at the other end in a bearing surface33 formed in a housing member 34. The housing member is attached't o andsupported at opposite ends by the sidewalls 12 and 13 of the frame 1 1.

As best seen in FIG. 2, the primary shaft 31 of a first embodiment ofthe odometer structure of this invention has a gear 36 thereon inmeshing engagement with the gear 27 of the cross-shaft 21. The primaryshaft also has a front portion 37 of a reduced diameter upon which adrive gear 38 is rotatably mounted. In turn, the drive gear 38 is inengagement with a gear 41 which is drivingly associated with a pluralityof odometer number wheels 42. The number wheels are mounted on a shaft43 supported atone end in a bearing sur face 44 formed in the sidewall12 and at the other end in a bearing surface formed in a member 46,which member is, in turn, secured to and supported by. the sidewall 13.The exact method and manner in which the gear 41 displaces the numberwheels 42 so as to indicate the total travel of the vehicle may take anyone of the many forms known in the prior art. Typical odometer drivestructures areshown in U.S. Pat. Nos. 3,] 16,875; 3,137,444; 3,250,468and 3,333,768.

Now with particular reference to FIG. 2, the first embodiment of theinterruptable drive connection formed between the primary shaft 31 andthe drive gear 38 supported thereon will be described in detail. In thecentral portion of the primary shaft a flange 51 is formed. This flangesupports a pair of cam members 52 thereon each definin'g a cam surface520. Each cam'member S2 terminatesat a dropoff 53. The drive gear 38 hasone or more projecting, deflectable tabs 56 thereon, one of whichis seenin FIG. 2. These tabs 56 are attached at one end 57 to the gear 38. Theattachment of the tab and gear may be accomplished by molding the gearand tab in a single plastic molding operation. Thelfree end 58 of eachtab .56 engagesone of the dropofis 53 and forms a driving connectiontherewith when the primary shaft 31 is rotated in the direction of arrowA of FIG. 2.

OPERATION Operation of the first embodiment structure for thenonreversible odometer of this invention is as follows. An input to theinput shaft 17 caused by forward travel of the motor vehicle is in sucha direction that the rotation of the primary shaft 31 is in thedirection of arrow A of FIG. 2. With such rotational directionestablished in the primary shaft 31, the dropoff 53 of each cam member52 forms a driving connection with the free end 58 of an associated tab56 of the drive gear 38. The drive gear, in turn, displaces the odometergear drive 41 whereby incremental displacements are occasioned in theodometer number wheels 42 thereby to increase the total indicateddistance of travel of thevehicle.

When a reverse input is supplied to the input shaft 17 in an attempt toreduce the total indicated distance on the odometer number wheels 42,the rotational movement delivered to the primary shaft 31 by thecross-shaft 21 is in a direction opposite to the direction indicated byarrow A of FIG. 2. With such a rotational movement delivered to theprimary shaft 31, the shaft is rotated in such a direction that the camsurface 52a of each of the cam members 52 is moved to engage initiallythe attached end 57 of an associated deflectable tab 56 and thereafterto move over the upper surface of the tab past the free end thereof. Insuch a manner, the free end 58 of the each tab 56 is moved up the camsurface 52a and then over 'the dropoff 53 repeatedly during the reverserotation of the primary shaft 31. When such a continued deflection ofthe projecting tabs occurs, no driving relationship is establishedbetween the primary shaft and the drive gear 38. When no drivingrelationship is established between these two elements, the odometergear drive 41 is not actuated and no displacement is occasioned in theodometer number wheels 42.

Thus, the first embodiment structure for the nonreversible odometer ofthis invention has been described. This odometer permits the recordationof actual distance covered when the vehicle is traveling in a normaldirection. Any attempts to reverse the input to the odometer and therebyto reduce the total indicated display of the odometer is stymied byinterrup tion of the drive connection between the input shaft and thegear drive associated with the odometer wheels.

SECOND EMBODlMENT Having described the preferred embodiment, a secondembodiment for the structure of the nonreversible odometer of thisinvention is shown in FIGS. 4, 5 and 6. in these figures like parts willbe designated by the same reference numerals as utilized in thedescription of the first embodiment structure.

In the second embodiment structure, the primary shaft 31 has a reducedportion 37 of increased length. A ring-shaped element 61 encircles theshafts reduced portion and is keyed thereto by a projecting internalportion 62 which is received within a recess 63 formed along the lengthof the reduced portion of the shaft (best seen in FIG. 6). The ring 62carries the cam members 52 thereon.

The drive gear 38 has associated therewith a pair of drive lugs 66, onlyone of which is seen in FIG. 4. A spring 67 also encircles the reducedportion 37 of the shaft 31 and acts between the back of the ring element61 and a larger portion of the shaft 31 to bias the ring element in sucha direction that the dropoff 53 of each of the cam members 52 is inengagement with its associated drive lug 66 of the drive gear 38.

When the shaft 31 is rotated in the direction of arrow A, the

dropoff 53 of each of the cam members 52 forms a driving relationshipwith the drive lugs 66 on drive gear 38 whereby the number wheels aredisplaced in a proper direction to record the total travel of thevehicle. On the other hand, when the primary shaft 31 is rotated in adirection opposite to the direction of arrow A of FIG. 4, the drive lugsare contacted by the cam surfaces 52a of the cam members 52 and the ringelement 61 is displaced upwardly as view in FIG. 4 against the bias ofthe spring. In such a manner, when the primary shaft 31 is rotated inthe wrong direction, the drive relationship between the shaft 31 and thedrive gear 38 is interrupted and a decrease does not occur on theodometer wheels in the total indicated travel of the vehicle.

There has been described herein a nonreversible odometer structurewherein the nonreversing feature is obtained by interrupting the driveconnection between the input member to the odometer and the displaydevice of the odometer. The nonreversible odometer in accordance withthis invention is relatively inexpensive to construct and extremelyreliable in operation.

What is claimed is:

l. A nonreversible odometer for use in a vehicle to indicate the totaldistance traveled by the vehicle, which odometer comprises:

a rame;

an input shaft rotatably mounted in said frame, said shaft beingdrivenby apparatus responsive to movement of the vehicle; a plurality ofnumber wheels supported for rotation in said frame for displaying anindication of the distance traveled by the vehicle;

gear drive means associated with said number wheels for rotativelydriving said number wheels to vary the displayed indication of thedistance traveled by the vehicle;

gear train means supported by said frame for interconnecting said inputshaft and said gear drive means so that rotation of said input shaftresults in displacement of said number wheels, said gear train meansincluding both a primary shaft and a drive gear rotatably mounted onsaid primary shaft, said drive gear being in driving engagement withsaid gear drive means associated with said number wheels and saidprimary shaft being driven when said input shaft is rotated; and

interruptable drive means interconnecting said primary shaft and saiddrive gear mounted on said shaft for interrupting the driving connectionbetween said two last mentioned elements when said primary shaft isdriven by said input shaft in a direction which would reduce the totaldisplayed travel indicated on said plurality of number wheels.

2. The nonreversible odometer as defined in claim 1 wherein: saidinterruptable drive means includes a ring encircling and keyed to saidprimary shaft for axial movement therealong, said ring having a slopingcam surface terminating in a dropoff facing said drive gear; a springencircling said primary shaft and biasing said ring toward said drivegear; and a lug on said drive gear extending toward said ring, said lugboth making driving contact with said dropoff of said ring when saidprimary shaft is rotated to increase the value of the display of saidnumber wheels, and said lug moving over said cam surface of said ringand off said dropoff of said cam surface during rotation of said primaryshaft in a direction opposite said direction causing an increase in thedisplayed distance of travel of the vehicle whereby said number wheelsare not driven through said gear drive means associated therewith.

1. A nonreversible odometer for use in a vehicle to indicate the totaldistance traveled by the vehicle, which odometer comprises: a frame; aninput shaft rotatably mounted in said frame, said shaft being driven byapparatus responsive to movement of the vehicle; a plurality of numberwheels supported for rotation in said frame for displaying an indicationof the distance traveled by the vehicle; gear drive means associatedwith said number wheels for rotatively driving said number wheels tovary the displayed indication of the distance traveled by the vehicle;gear train means supported by said frame for interconnecting said inputshaft and said gear drive means so that rotation of said input shaftresults in displacement of said number wheels, said gear train meansincluding both a primary shaft and a drive gear rotatably mounted onsaid primary shaft, said drive gear being in driving engagement withsaid gear drive means associated with said number wheels and saidprimary shaft being driven when said input shaft is rotated; andinterruptable drive means interconnecting said primary shaft and saiddrive gear mounted on said shaft for interrupting the driving connectionbetween said two last mentioned elements when said primary shaft isdriven by said input shaft in a direction which would reduce the totaldisplayed travel indicated on said plurality of number wheels.
 2. Thenonreversible odometer as defined in claim 1 wherein: said interruptabledrive means includes a ring encircling and keyed to said primary shaftfor axial movement therealong, said ring having a sloping cam surfaceterminating in a dropoff facing said drive gear; a spring encirclingsaid primary shaft and biasing said ring toward said drive gear; and alug on said drive gear extending toward said ring, said lug both makingdriving contact with said dropoff of said ring when said primary shaftis rotated to increase the value of the display of said number wheels,and said lug moving over said cam surface of said ring and off saiddropoff of said cam surface during rotation of said primary shaft in adirection opposite said direction causing an increase in the displayeddistance of travel of the vehicle whereby said number wheels are notdriven through said gear drive means associated therewith.